Japan aircraft carrier plan outrage

JAPAN can't have aircraft carriers. And just to be sure, it officially declared several of its latest warships must be called "helicopter destroyers" - even though to all intents and purposes they look like aircraft carriers.

They just don't carry fixed-wing aircraft. Yet.

They carry helicopters.

It's been a tenuous splitting of hairs ever since the Japanese Maritime Self-Defence Force introduced its new 25,000 ton flat-topped Izumo-class aviation ships to service in recent years.

Article 9 of the Japanese constitution dictates that Tokyo will "forever renounce war as a sovereign right of the nation ... land, sea, and air forces, as well as other war potential, will never be maintained ..."

Historically, this has been interpreted as allowing Japan military forces of a purely defensive character.

But a full-blown aircraft carrier is a mobile military base.

They are inherently offensive by nature.

CHINA ALARMED

Beijing has today warned Japan to "act prudently" after reports of Japan's possible intention to buy the F-35B variant of the controversial stealth strike fighter.

It's designed to operate off aircraft carriers. Particularly small ones.

Its mission is to support marines and soldiers establish a 'beach head' on hostile soil.

"We urge Japan to do more that may help enhance mutual trust and promote regional peace and stability," Beijing's spokeswoman said.

Earlier this year China launched its second aircraft carrier, and its first - Liaoning - embarked on several intensive war-game exercises.

ASIAN ARMS RACE

Beijing's recent bold expansion into the South China Sea through the construction of illegal artificial islands in order to establish well equipped and heavily defended fortresses has dramatically raised tensions throughout Asia and the Pacific.

But it has also ramped-up its rhetoric over the disputed Senkaku island chain in the East China Sea, over which both it and Tokyo claim ownership.

Fishing fleets backed up by Chinese coast guard and naval vessels have repeatedly entered the waters around the islands in recent years, and more recently several flights by combat aircraft have passed nearby.

Tokyo has responded by repositioning naval patrol vessels, missile defence systems and fighter aircraft squadrons to the area - including the major joint-US military base island of Okinawa.

It has also been steadily rebuilding its defence forces.

Japanese Prime Minister Shinzo Abe this year approved a record $US46 billion defence budget for 2018. He justified it as a response to North Korea's belligerent behaviour and China's "growing military presence".

Japan's Izumo 'helicopter destroyer'. Tokyo is considering converting this and another ship of the class to be capable of operating F-35B stealth 'jump jets'.

IZUMO CARRIERS

At the centre of the growing diplomatic storm are Japan's two new Izumo-class ships.

Whatever they're chosen to be called, they're currently capable of operating about 14 helicopters tasked with hunting down submarines.

Izumo and Kaga are the biggest ships Japan has built since World War II, measuring some 248m long and 38m wide. At 25,000 tons, its size is similar to that of the recently decommissioned British Invincible class of short takeoff and vertical landing (jump jet) carriers. It's bigger than those operated by Spain and Italy.

Like Australia's new Canberra-class landing helicopter dock (LHD) ships, Izumo can also carry troops - some 400 marines - and about 50 light vehicles. It does not carry landing craft to deploy them, however, instead relying upon embarking specialist heavy helicopters for the job.

Royal Australian Navy ships Adelaide, Toowoomba and Darwin in formation off the coast of Sydney. HMAS Adelaide has a ski ramp, but no F-35Bs. Picture: Defence

Neither Izumo or Kaga have catapults - or a ski jump along the line of Australia's Canberra class - intended to help fling fixed-wing aircraft like the F-35B into the air.